2'2 Nutrition and Energy Flow

1
2.2 Nutrition and Energy Flow
An important characteristic of a species niche
is how it obtains energy.
2
The producers Autotrophs an organism that uses
light energy or energy stored in chemical
compounds to manufacture food. Examples 1.
plants
2. Unicellular organisms such as algae
3. cyanobacteria
3
The consumers Heterotrophs an organism that
cannot make its own food and feed on other
organisms

• Herbivores - heterotrophs that feeds only on
  plants
• a. rabbits

b. grasshoppers
c. elephants
d. fruit eating bats
4

• Carnivores heterotrophs that eat other
  heterotrophs
• a. lions

b. sharks
c. wolves
d. Tasmanian devil
5
3. Omnivores organisms that eat both autotrophs
and heterotrophs a. humans
b. raccoons
c. opossums
d. bears
6

• Scavengers heterotrophs that do not kill for
  food but instead, eat animals that are already
  dead.
• a. vultures

b. spotted hyena
c. springtails
d. seagulls
7
5. Decomposers are organisms that break down
complex compounds of dead and decaying plants and
animals into simpler molecules that can be more
easily absorbed. a. bacteria
b. fungi
c. termites
8
Flow of Matter and Energy in Ecosystems
Energy and matter never leave or disappear
from our environment. Instead, these essential
elements are transformed or re-cycled into
different venues.
9
Food chains Pathways for matter and energy - a
food chain is a simple model that scientists use
to show how matter and energy move through an
ecosystem. The natural flow is from autotrophs
to heterotrophs and, eventually, to decomposers
10
Trophic levels - represent links in the food
chain. Autotrophs start the process and are
located at the bottom of the trophic pyramid
model. This represents the largest portion of
the pyramid the base. Why? In other words,
what is the correlation between the base of a
pyramid and autotrophs???
11
Each subsequent level on the trophic model is
smaller and located above the previous level.
3rd order heterotrophs
2nd order heterotrophs
1st order heterotrophs
autotrophs
12
These ecological pyramids may represent different
types of data so be sure to study the pyramid
carefully before making any conclusions. These
include the following 1. energy
2. numbers
3. biomass
13
In the pyramid of energy, some of the energy
transferred at each successive trophic level
enters the environment as heat (shown in next
slide)
14
(No Transcript)
15
Another model that is used by ecologist is a food
web. This is a more realistic model than a food
chain because it includes the complex
relationships that exist between organisms.
16
Cycles in Nature food chains, food webs, and
ecological pyramids are all models that show how
energy moves in only one direction. Matter,
however, is constantly recycled. Because there
is a variety of important matter in the
environment, it is beneficial for scientist to
break the total amount of matter down into
several different models.
17
1. Water Cycle essential to all life
18
2. Carbon Cycle all life on Earth is based on
carbon molecules. Atoms of carbon form the
framework for proteins, carbohydrates, fats, and
other important molecules.
19
(No Transcript)
20
3. Nitrogen Cycle nitrogen is an important
element with regard to plants. Plants use
nitrogen to make important molecules such as
protein. They are not efficient at gaining
nitrogen from the atmosphere. Instead, plants
get most of the needed nitrogen from the soil.
21
(No Transcript)
22
4. Phosphorus Cycle all organisms require
phosphorus for growth and development